The infant version, however, is generally far less severe than the adult form of botulism - and is very rare in the UK.

It is caused by eating the spores of a particular bacterium, Clostridium botulinum, or poisons produced by the spores.

The spores are particularly hardy - they have to be boiled for half an hour to kill them - however, gentler cooking for the same period is enough to destroy the dangerous toxin.

The most common method of getting botulism is from poorly-processed foods which are then vacuum sealed, or sealed with very little air in containers.

This is because the bacterium grows best when there is no oxygen around.

Improved food safety processes mean that tinned and packaged foods are a far rarer source of the bacterium than before.

Another potential source for spores is honey - which, though safe for children and adults, should not be given to babies under 12 months of age.

Symptoms

In adults, symptoms will emerge between 18 and 36 hours after eating the contaminated food.

The problem is that the bacterium produces a toxic chemical which simply is not broken down in the normal way by the digestive processes of the gut.

It is this toxin, one of the most potent in the world, which causes the major health complications associated with botulism.

It is a nerve toxin, which quickly moves to the central nervous system and affects many of the key functions of the body.

First the adult will have difficulty walking and swallowing, and perhaps impaired vision.

This, depending on the amount of toxin involved, and the speed with which the illness is recognised and treated, can progress to convulsions and perhaps even to paralysis of the muscles needed to breathe.

Upwards of two-thirds of adults affected this way will die.

The difference between infant botulism and adult botulism is that in infants, the toxin is produced by the bacteria while they are in the body, while the adult version is usually caused by eating toxin which has already been produced by the bug within food.

Treatment

Speed is of the essence if a serious case of botulinum toxin poisoning is detected.

There is an anti-toxin drug available, but this may not be able to work if the quantity of toxin ingested is high.

Infants who fall ill with botulism can require a lengthy period of hospitalisation to recover. In some cases, they may die.

Key symptoms to look out for are constipation, allied with weakness, and a weak cry.

However, there have been only a handful of cases in the UK over the last 10 years - a sign that, on the whole, food processing is remarkably safe.

And what is even more remarkable is the harnessing by doctors of the feared botulinum toxin as a potential treatment.

The tiny Botox injections - with their amazing ability to paralyse muscle - are now a commonplace way of dealing with everything from excessive sweating to wrinkles and involuntary eye movements.